use HTTP_PROXY in transport object for registry endpoint if defined in environment

Author: derdanne

pkg/registry/endpoints.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"math"
 	"net/http"
+	"net/url"
+	"os"
 	"strings"
 	"sync"
 	"time"
@@ -208,11 +210,20 @@ func (ep *RegistryEndpoint) DeepCopy() *RegistryEndpoint {
 
 // GetTransport returns a transport object for this endpoint
 func (ep *RegistryEndpoint) GetTransport() *http.Transport {
+	transport := http.Transport{}
 	tlsC := &tls.Config{}
+
 	if ep.Insecure {
 		tlsC.InsecureSkipVerify = true
 	}
-	return &http.Transport{TLSClientConfig: tlsC}
+	transport.TLSClientConfig = tlsC
+
+	if proxy, ok := os.LookupEnv("HTTP_PROXY"); ok {
+		proxyUrl, _ := url.Parse(proxy)
+		transport.Proxy = http.ProxyURL(proxyUrl)
+	}
+
+	return &transport
 }
 
 func init() {